1. Field of the Invention
This invention relates generally to data input devices and more particularly to a handwriting recognition system.
2. Antecedents of the Invention
The traditional data input device for processor implemented systems such as personal computers comprised a keyboard. Keyboards were accurate, reliable and cost effective.
Requirements for data input systems expanded beyond computers, however, to processor implemented devices such as hand held devices, e.g. organizers, cellular telephones and pagers. Due to the small size of these devices, keyboard based data input was impractical. These devices were designed to be hand held and carried on one""s belt or in a pocket. Further, these devices were configured for data input while the user was in transit, while standing, walking, etc., without space to rest a keyboard for data input.
In some systems, a key pad was employed for data input with the input data being selected by the number of times a specific key was pressed. For example, the number 5 key corresponded to the letters J, K and L. Successive depressions of the number 5 key resulted in display of the letters J, K and L successively.
A further approach utilizing the key pad was to scroll through the letters J, K and L when the number 5 key was depressed. Another key pad based data input system was premised upon statistical linguistics which selected the most common word after only a few initial letters were keyed.
Further data input systems were premised upon recognition of handwritten symbols having separated shapes. The symbols were configured for ease in the recognition process, such as unistroke symbols described in U.S. Pat. No. 5,596,656 issued to GOLDBERG. Users, however, had a tendency to write in the natural manner rather than in artificial unistrokes and as a result, recognition levels suffered. Other handwriting recognition systems placed constraints upon natural writing and thus did not achieve high recognition levels.
A handwriting recognition system suitable for data input in hand held processor implemented devices includes a writing surface, e.g. a touch pad, having a finite number of discrete points at predetermined spaced locations. A user inputs data by writing on the touch pad, as by a stylus, characters such as letters, symbols and numbers following a predetermined sequence of points.
Alphabet letters, numbers and punctuation symbols can be recognized utilizing a writing surface with a grid having as little as nine points. When a grid having twelve points is utilized, a reference base line is obtained to simplify writing and recognition of letter characters having depending portions.
For each letter, number or symbol, there is a specified sequence of mandatory xe2x80x9canchorxe2x80x9d points through which the stylus must sequentially pass within a predetermined minimum distance and a specified number of xe2x80x9coptionalxe2x80x9d points which the stylus may, but is not required to pass through.
The user enters data in substantially a natural handwriting format with characters being written to conform with the sequential points path requirements of the recognition system.
From the foregoing compendium, it will be appreciated that it is a consideration of the present invention to provide a handwriting recognition system of the general character described which is easy to learn and to use.
An aspect of the present invention is to provide a handwriting recognition system of the general character described which achieves a high recognition rate.
It is a feature of the present invention to provide a handwriting recognition system of the general character described which is relatively low in cost.
Another consideration of the present invention is to provide a handwriting recognition system of the general character described which achieves a high rate of throughput.
A further aspect of the present invention is to provide a handwriting recognition system of the general character described which utilizes but a minimal amount of processing power.
To provide a handwriting recognition system of the general character described with minimal memory requirements is another feature of the present invention.
Yet another consideration of the present invention is to provide a handwriting recognition system of the general character described which is well adapted for employment with writing surfaces of limited size.
Another aspect of the present invention is to provide a handwriting recognition system of the general character described which is capable of being integrated inside the controller of a touch pad.
Yet a further feature of the present invention is to provide a handwriting recognition system of the general character described adapted for implementation with a touch enabled screen of a cellular telephone.
A further aspect of the present invention is to provide a handwriting recognition system of the general character described which employs a natural handwriting format.
Other considerations, features and aspects in part would be obvious and in part would be pointed out hereinafter.